Support newer node versions

[Hannes Krumbiegel]

Thanks a lot for developing this project! The result is pretty impressive.

Currently, the package.json only specifies that Node 18 is supported. It would be nice if newer Nodes could be used. I just tried it with Node 21 (the "Echo" Chat mode), and it seemed to work.

[Kasumi]

Thanks for letting me know! Fixed here 4bb9038

[Hannes Krumbiegel]

Thanks!